1. Field of the Invention
Embodiments of the present invention generally relate to an apparatus and a method for processing semiconductor substrates. More particularly, embodiments of the present invention provide apparatus and method for cleaning semiconductor substrates.
2. Description of the Related Art
During fabrication of a semiconductor device, various layers, such as oxides, copper, require planarization to remove steps or undulations prior to formation of subsequent layers. Planarization is typically performed mechanically, chemically, and/or electrically by pressing a device side of a semiconductor substrate against a polishing pad which is saturated with a polishing solution, such as an abrasive compound, and by rotating the polishing pad relative to the semiconductor substrate. Multiple steps of polishing are generally performed using different polishing pads and polishing solutions to achieve desired flatness and smoothness on the device side.
The planarization process is generally followed by a cleaning process which removes residual of the polishing solutions and/or particles from polishing. Conventional cleaning processes generally include scrubbing the substrate surfaces with mechanical scrubbing devices using brushes made from porous or sponge like materials, such as polyvinyl acetate (PVA), or brushes made with nylon bristles. Additionally, one or more nozzles that output sonically energized fluid may be used in combination with the brushes. Scrubbing and spraying may remove majority of residual polishing solution and other particles on the substrate surfaces. However, conventional cleaning processes usually fail to remove particles in deep trench of a patterned substrate and the substrates are also susceptible to damages caused by conventional cleaning.
Therefore, there is a need for an apparatus and method to remove particles in deep trenches of a substrate surface and to reduce damages during cleaning.